真实描绘现实中的环境或物体的光影是计算机图形学中一个重要的课题，最常用的一个方法是光线追踪显示法，即当光线进入物体中间时候，计算（追踪）光的路径-Depict the true reality of the environment or the objects in computer graphics lighting is an important issue, the most commonly used method is a ray tracing display, that is, w